Base for a pH meter electrode arm



FIG. 1 is a left front perspective view of a base for a pH meter electrode arm showing my new design;

FIG. 2 is a top plan view thereof, the bottom being substantially flat, plain, and unornamented;

FIG. 3 is a right side elevational view of FIG. 2;

FIG. 4 is a front elevational view thereof, with the rear elevational view being a mirror image. 

The ornamental design for a base of a pH meter electrode arm, as shown and described. 